Information recording device for video and sound

ABSTRACT

An information recording device by means of which the information signal such as the picture signal, the sound signal and others are recorded on a recording medium and the information reproduced from the recording medium on which the information has been registered and that from other sources is recorded again on the same recording medium selectively either individually or mixed.

This is a continuation of application Ser. No. 335,339 filed Dec. 29,1981 and now U.S. Pat. No. 4,480,273.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an information recording device bymeans of which an information signal such as a picture signal, a soundsignal and the line are recorded on a recording medium and newinformation is added to the recording medium on which the initialinformation has been recorded.

2. Brief Description of the Prior Art

In the present specification, the video tape recorded (VTR) making useof magnetic tape and a magnetic head is used as an example.

In the conventional type VTR using a cassette and a magnetic head, thepicture signal is recorded on an inclined track by means of a rotaryhead, while the control signal and the sound signal are recorded on thetwo straight tracks at both ends of the magnetic tape. An example ofsuch a helical scanning type cassette VTR is shown in FIG. 1.

In the drawing, the tape has been loaded in the VTR. The apparatusincludes a cassette 1, a magnetic tape 2, and rotary magnetic heads 3and 4 arranged on a rotary head drum. The capstan 9 and the pinch roller8, feed the tape 2 in the direction of the arrow 10 at a constant speed.In this way, the magnetic tape 2 runs along the circumference of thehead drum, whereby along with the rotation of the rotary heads 3 and 4in the direction of the arrow 11 the inclined track is formed on themagnetic tape 2. The erasing head 5 is provided for erasing the totalwidth of the tape 2, the erasing head 6 is only for erasing the soundtrack and the recording reproducing head cooperates only with the soundtrack and the control signal track.

FIG. 2 shows an example of the pattern on the magnetic tape on which theinformation is recorded by means of the VTR in FIG. 1. There is shown inthe drawing, a track 12 for recording the control signal, a track 13 forrecording the sound signal and a video track 14 on which the picturesignal is recorded by means of the two rotary magnetic heads 3 and 4,whereby the 1-line 1-field video signal is recorded in accordance with aconventional azimuth recording system. Furthermore, the sound signal isrecorded by means of the fixed head 7 on the sound track, at a firstlateral extremity of the tape, while at the same time, the CTL signalfor obtaining the synchronization at the time of reproduction isrecorded on the control track 12 at the other lateral extremity.

In the above described conventional system in order to carry out soundpost recording, the sound signal recorded on the sound track 13 iserased by means of the erasing head 6, which cooperates exclusively withthe sound track, and a new sound signal is recorded by means of thefixed head 7.

On the other hand, in order to lower the quantity of required magnetictape, to have a compact and light cassette and cooperating apparatus,the width of the recording track is narrowed and to the running speed ofthe magnetic tape is decreased and the recording density of the picturesignal is increased. However, when the running speed of the magnetictape is decreased substantially, it is difficult to maintain frequencycharacteristics sufficient for a sound signal fixed head. Under suchcircumstances a system is considered in which the signal composed of thepicture signal and the sound signal is recorded and reproduced by meansof the same rotating magnetic head. However, in accordance with thissytem, the picture signal and the sound signal are recorded composed, sothat post recording of the sound signal is impossible.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an informationrecording device free from the above shortcomings, more particularly bymeans of which it is possible to post record the sound on the samerecording medium as that the picture and on which the sound have beenrecorded simultaneously. As described throughout this specification,"post recording" refers to later recording of a additional or new soundsignal on the recording medium that was used in previously recording theinformation signal (e.g., a picture signal and sound signal).

It is another object of the present invention to provide an informationrecording device in which the track for the post recording isexclusively provided on the above recording medium.

It is another object of the present invention to provide an informationrecording device by means of which the simultaneously recorded soundsignal and the post recorded sound signal can be reproduced selectivelyor simultaneously.

It is a further object of the present invention to provide aninformation recording device by means of which the informationreproduced from the recording medium and that from other sources arecombined and recorded on the same recording medium as that on which theinformation is reproduced.

Other objects of the present invention will be obvious from theexplanation below in accordance with the accompanying drawings.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 shows the recording reproducing part as an example of simpleconventional VTR.

FIG. 2 shows the pattern of the recording track on the magnetic tapewith the device shown in FIG. 1.

FIG. 3 shows the pattern of the recording track on the magnetic tapewith the present embodiment of the information recording device.

FIG. 4 shows the frequency bands of the recording signals of the presentembodiment.

FIG. 5 shows a block diagram of an embodiment of the circuit in theinformation recording device.

FIG. 6 shows the frequency bands of the pilot signal and the soundsignal on a track exclusively for sound of the present embodiment of thedevice.

FIG. 7 shows, in greater detail, a portion of the circuit shown in FIG.5.

FIG. 8 shows an embodiment of the recording reproducing part of theinformation recording device of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENT

FIG. 3 shows an example of the pattern of the magnetic tape of thepresent embodiment of the magnetic recording reproducing device.

In the drawing, the CTL signal recording track and 19 is the inclinedtrack on which the picture and the sound signal is recorded in azimuthby means of the rotary magnetic head is identified by the referencenumeral 19. The track 51 is exclusively for recording sound.

FIG. 4 shows an example of the curve of the frequency band of thepicture and the sound signal when the signal composed of the picturesigal and the sound signal is recorded by means of the rotary magnetichead. In the drawing, the band 15 for the color signal C is converted inthe low band, 17 is the band for the brightness signal Y modified infrequency and the band 16 is for the sound signal AU modified infrequency. The above band definition is only an example, since othercombination are also possible. The above signals C, Y and AU arerecorded on the inclined track 19 shown in FIG. 3.

FIG. 5 shows the block diagram of an embodiment of the electric circuitfor the normal recording and reproducing as well as the sound postrecording of the VTR in accordance with the present invention. In thedrawing, at the time of normal recording the recording reproducingsignal change over analog switch 24 assumes the recording mode (Rec) andthe picture signal is input, when by means of the low pass filter (LPF)20 for picking up the brightness signal the brightness component Y ofthe picture signal is picked up, modified in frequency by means of thefrequency modulator 21 and delivered to the mixer 22. Furthermore, thecolor signal component of the picture signal is picked up by means ofthe band pass filter (BPF) 25, converted in the low band pass frequencyby means of the frequency converter for converting the color signal Cinto the low band and delivered to the mixer 22.

On the other hand, the sound signal is modified in frequency by means ofthe frequency modulator 27 and delivered to the mixer 22.

As shown in FIG. 4, the frequency band 16 for sound is situated betweenthe frequency band 15 for the color signal converted in the low band andthe frequency band 17 for the brightness signal modified in frequency.The output of the mixer 22 is delivered to the recording amplifier 23and then to the rotary magnetic head 29 through the Rec terminal of theanalog switch 24 to be recorded on the inclined track 19 of the magnetictape 45.

Furthermore, at the time of normal reproduction, the analog switch 24assumes the reproducing mode (Play) and the post recording signal andthe normal reproducing signal change over analog switch 30 is connectedto the terminal N. Namely, the picture and the sound signal reproducedby means of the rotary magnetic head 29 are delivered to the reproducingamplifier 28 through the analog switch 24. The output of the reproducingamplifier is delivered to the high pass filter (HPF) 31, LPF 34 and BPF36. The HPF 31 picks up the brightness signal Y (band 17 in FIG. 4)modifier the frequency and delivers it to the mixer 33 through thefrequency demodulator 32. The LPF 34 picks up the color signal C (band15 in FIG. 4) converted in low frequency, whereby the color signaldemodulated by means of the frequency demodulator 35 is delivered to themixer 33. The output of the mixer 33 becomes the reproduced picturesignal. On the other hand, the sound signal (band 16 in FIG. 4),modulated in frequency, is delivered to the frequency demodulator 37through the BPF 36 and taken out as the sound signal through the analogswitch 30.

In the present embodiment of the device, in order to make post recordingof the sound possible, a track and a fixed magnetic head 44 are providedexclusively for sound.

At the time of the post recording of the sound, the analog switch 46 ischanged over to the terminal A position. The sound signal separated fromthe signal composed of the picture and the sound signal is delivered tothe mixer 38 through the frequency demodulator 37. On the other hand,the post recording sound signal (PRAU) is also delivered to the mixer38, whereby the mixing ratio of the sound signal (AU) before postrecording with that (PRAU) for post recording is varied freely by meansof the mixing ratio adjuster 39 belonging to the mixer 38. The output of38 is delivered to the mixer 40 and added with the pilot signal by meansof the pilot signal generator 41. Hereby, as is shown in FIG. 6, thefrequency of the pilot signal 52 is chosen 10 Hz lower than the band 53for sound. Hereby, the band for the pilot signal can be any one whichgives no influence to the sound signal. This pilot signal will now bedescribed together with the reproduction of the sound signal from thesound track 51. The output of the mixer 40 is delivered to the recordingamplifier and the bias device 42, in which the bias signal is added bymeans of the bias signal generator 43. The output of the circuit 42 isrecorded on the rack 51 (exclusively for the sound) on video tape 45 bymeans of the fixed magnetic head 44 (exclusively for sound) through theanalog switch 46.

When the reproduction mode is assumed after recording on the track 51(exclusively for the sound), analog switches 24 and 46 are changed overto the terminal P position. The output of the fixed head 44 is connectedto the reproducing amplifier 47 through the analog switch 46. The outputof the reproducing amplifier 47 is directed to the band pass filter(BPF) 48, which allows the passage of the sound signal (band 53 of FIG.6). The band pass filter (BPF) 49 picks up the pilot component (band 52in FIG. 6) from the output of the reproducing amplifier 47. The outputof the BPF 49 is delivered to the pilot signal detector 50, whichchanges over the analog switch 30 to the terminal A position at the timeof the detection of the pilot signal. The sound signal which has passedthe BPF 48 is taken out through the analog switch 30. Namely, when thepilot signal is present the sound signal recorded on the exclusive track51 is taken out of the sound output line 70. This output sound signal iscomposed of the post recording sound signal input in the mixer 38 andthe sound signal reproduced from the original recording track at thedesired mixing ratio. On the other hand, when the pilot signal isabsent, the analog switch 30 is changed over to the N position and theseparated sound signal reproduced from the picture and sound track istaken out of the sound output line 70.

The mixer 38 and the adjuster 39 are constructed as is shown in FIG. 7.

In the drawing, a standard power source is identified by the referencenumeral Vcc, a condenser C, a resistor R,a transistor TR; the inputvoltage VA from the frequency modulator 37, the input voltage VB fromthe post recording sound signal, the output voltage Vout and thevariable resistor is identified by the reference numeral VR.

Now let us suppose that the voltage dividing ratio of VR is K : (1-K)and the total resistance VR is r. Then, the following relations areobtained. ##EQU1## Therefore, Hereby, K can be chosen in such a mannerthat 0≦K≦1. Thus, only VA or only VB can be taken out or VA and VB canbe mixed at the proper ratio. Namely, the already recorded sound signaland the post recording sound signal can be recorded on the trackexclusively for sound selectively or at the desired mixing ratio.

FIG. 8 shows the construction of the recording reproducing part as anembodiment of a simple VTR in accordance with the present invention. Inthe drawing, 55 is the cassette for loading the magnetic tape 56, andthe rotary magnetic heads 57 and 58 are for recording and reproducingthe picture and sound signal. The rotary magnetic heads 57 and 58 rotatein the direction of the arrow 64 at a constant speed. The capstan isidentified by the reference numeral 60, while the pinch roller isidentified by the reference numeral 60, whereby the tape 56 is under thepressure of the capstan 60 and the pinch roller 59 to be fed in thedirection of the arrow 63 along with the constant rotation of thecapstan. The erasing head 61 is for erasing the total width of the videotape, the fixed head 62 is for recording and reproducing the CTL signaland the fixed head 65, in accordance with the present invention, is forexclusively recording and reproducing the signal.

Furthermore, in order to make the re-post-recording on the soundrecording tape possible, it is possible to arrange an erasing head forerasing the track, (exclusively for the sound) before the fixed head 65exclusively, (for sound) along the running direction of the tape.

In accordance with the invention the system for recording andreproducing the signal composed of the picture signal and the soundsignal of the VTR. Post recording of sound is made possible, while aselective means is provided to record the post recording sound signaland the sound signal of the composed signal at the desired ratio whenthe tape on which the picture and sound signal and the post recordingsound signal are recorded is reproduced, which is remarkably effectivefor editing the sound information on VTR.

Furthermore, in accordance with the present invention, the informationreproduced from the recording medium and the information from other newsources can be mixed and post recorded on the same recording medium. Inaccordance with such construction, new information can be added at thetime of the post recording, whereby the already recorded information isnot erased. Furthermore, by making the mixing ratio of the reproducedinformation and that from other sources adjustable the level can beselected in accordance with the wish of the editor. Particularly, in thecase of sound information, selecting the mixing ratio, various modes canbe expected as the background music or the song is recorded. Thus, theinformation recording device, in accordance with the present invention,can be applied not only to the present embodiment of VTR by also to thetape recorder or disc recorder for audio purposes and the like.

The present invention is not limited to the above embodiment and can bemodified and applied in many ways within the gist of the invention.

What is claimed is:
 1. A video tape recorder comprising:first mixingmeans for mixing a picture signal and a first sound signal to form afirst mixed signal; first recording means for recording the first mixedsignal on a tape-shaped recording medium; first reproducing means forreproducing the first mixed signal from the medium; separating means forseparating the first sound signal from the first mixed signal reproducedby said first reproducing means; second mixing means for mixing thefirst sound signal separated by said separating means with a secondsound signal from another source to form a second mixed signal; andsecond sound recording means for recording the second mixed signal onthe medium.
 2. A video tape recorder according to claim 1, furthercomprising:adjusting means for adjusting the mixing ratio of said firstand second sound signals at said second mixing means.
 3. A video taperecorder according to claim 1, further comprising:second reproducingmeans for reproducing the second mixed signal from the medium.
 4. Avideo tape recorder according to claim 3, further comprising:outputmeans for selectively outputting the first sound signal and the secondmixed signal.
 5. A video tape recorder according to claim 4, furthercomprising:control means for controlling said output means on the basisof the output of said second reproducing means.
 6. A video tape recorderaccording to claim 5, further comprising:generating means for generatinga pilot signal for indicating that the second mixed signal is beingrecorded.
 7. A video tape recorder according to claim 6, wherein saidsecond recording means records the pilot signal at the same time as thesecond mixed signal, while said control means controls said output meanson the basis of the pilot signal reproduced by said second reproducingmeans.
 8. A video tape recorder according to claim 7, wherein when saidsecond reproducing means reproduces the pilot signal, said control meanscontrols said output means to output said second mixed signal.
 9. Avideo tape recorder according to claim 8, wherein the tape-shapedrecording medium is a magnetic tape and the first recording meansincludes at least one magnetic head.
 10. A video tape recorder accordingto claim 9, wherein the first recording means further includes acylindrical guide body for guiding disposed around the magnetic tape,and rotating means for rotating the magnetic head to record the firstmixed signal on the magnetic tape.
 11. A video tape recorder accordingto claim 10, wherein the second recording means includes a fixedmagnetic head for recording the second mixed signal on the magnetictape.
 12. A video tape recorder comprising:(a) frequency modulationmeans for frequency modulating a first audio signal; (b) first recordingmeans for recording the frequency modulated first audio signal and avideo signal on a first area of a magnetic tape, said first recordingmeans including at least one rotating hand; (c) first reproducing meansfor reproducing the frequency modulated first audio signal and the videosignal from the first area of the magnetic tape; (d) demodulation meansfor frequency demodulating the first audio signal reproduced by saidfirst reproducing means; (e) mixing means for mixing a second audiosignal and the first audio signal demodulated by said demodulation meansto form a mixed audio signal; (f) adding means for forming a bias-addedaudio signal by adding a bias signal to the mixed audio signal; (g)second recording means for recording the bias-added audio signal on asecond area of the magnetic tape, said second recording means includinga fixed head; (h) second reproducing means for reproducing thebias-added audio signal from the second area of the magnetic tape; and(i) taking away means for taking away the bias signal from thebias-added audio signal reproduced by said second reproducing means. 13.A recorder according to claim 12, further comprising moving means formoving the magnetic tape in its longitudinal direction.
 14. A recorderaccording to claim 13, wherein the first area of the magnetic tape andthe second area of the magnetic tape are respectively continuous in thelongitudinal direction of the magnetic tape.
 15. A recorder according toclaim 14, wherein the rotating head traces the first area in an obliquedirection.
 16. A video tape recorder comprising:(a) first mixing meansfor mixing a video signal and a first audio signal to form a compositesignal; (b) first recording means for recording the composite signal ona first area of a magnetic tape, said first recording means including atleast one rotating head; (c) first reproducing means for reproducing thecomposite signal from the first area of the magnetic tape; (d)separation means for separating the first audio signal and the videosignal from the composite signal reproduced by said first reproducingmeans; (e) second mixing means for mixing a second audio signal and thefirst audio signal separated by said separation means to form a mixedaudio signal; (f) second recording means for recording the mixed audiosignal on a second area of the magnetic tape, said second recordingmeans including a fixed head; and (g) second reproducing means forreproducing the mixed audio signal from the second area of the magnetictape.
 17. A recorder according to claim 16, further comprising movingmeans for moving the magnetic tape in its longitudinal direction.
 18. Arecorder according to claim 17, wherein the first area of the magnetictape and the second area of the magnetic tape are respectivelycontinuous in the longitudinal direction of the magnetic tape.
 19. Arecorder according to claim 18, wherein the rotating head traces thefirst area in an oblique direction.
 20. A video tape recordercomprising:(a) frequency modulation means for frequency modulating afirst audio signal; (b) first recording means for recording thefrequency modulated first audio signal and a video signal on a firstarea of a magnetic tape, said first recording means including at leastone rotating head; (c) first reproducing means for reproducing thefrequency modulated first audio signal and the video signal from thefirst area of the magnetic tape; (d) demodulation means for frequencydemodulating the first audio signal reproduced by said first reproducingmeans; (e) adding means for adding a bias signal to a second audiosignal to form a bias-added second audio signal; (f) second recordingmeans for recording the bias-added second audio signal on a second areaof the magnetic tape, said second recording means including a fixedhead; (g) second reproducing means for reproducing the bias-added secondaudio signal from the second area of the magnetic tape; (h) taking awaymeans for taking away the bias signal from the bias-added second audiosignal reproduced by said second reproducing means; and (i) outputcontrol means for setting the output mode of the device at least to thefollowing two modes:a first output mode by which only the video signalreproduced by said first reproducing means and the first audio signaldemodulated by said demodulation means are simultaneously output; and asecond output mode by which only the video signal reproduced by saidfirst reproducing means and the second audio signal taking away the biassignal by said taking away means are simultaneously output.
 21. Arecorder according to claim 20, wherein said output control meansincludes a wave detection circuit which detects the wave of thebias-added second audio signal reproduced by said second reproducingmeans.
 22. A recorder according to claim 20, further comprising movingmeans for moving the magnetic tape in its longitudinal direction.
 23. Arecorder according to claim 22, wherein the first area of the magnetictape and the second area of the magnetic tape are respectivelycontinuous in the longitudinal direction of the magnetic tape.
 24. Arecorder according to claim 23, wherein the rotating head traces thefirst area in an oblique direction.
 25. A video tape recordercomprising:(a) frequency modulation means for frequency modulating afirst audio signal; (b) first recording means for recording thefrequency modulated first audio signal and a video signal on a firstarea of a magnetic tape, said first recording means including at leastone rotating head; (c) input means for inputting a second audio signal;(d) adding means for forming a bias-added audio signal by adding a biassignal to an audio signal including the second audio signal; (e) secondrecording means for recording the bias-added audio signal on a secondarea of the magnetic tape, said second recording means including a fixedhead; and (f) output means for outputting a mixed audio signal which isformed by mixing the first audio signal and the second audio signal. 26.A video tape recorder comprising:(a) mixing means for mixing a videosignal and a first audio signal to form a composite signal; (b) firstrecording means for recording the composite signal on a first area of amagnetic tape, said first recording means including at least onerotating head; (c) input means for inputting a second audio signal; (d)second recording means for recording an audio signal including thesecond audio signal; and (e) output means for outputting a mixed audiosignal which is formed by mixing the first audio signal and the secondaudio signal.